Clutch release hydraulic drive (Fig. 1) for cars of the UAZ-31512 family consists of a suspension pedal 19, a master cylinder 5, a hydraulic tube 4, a hydraulic hose 24 and a working cylinder 25
The clutch release hydraulic drive for UAZ-3741 family cars is similar and is shown in fig. 2.
Fig. 1. Clutch release hydraulic drive for cars of the UAZ-31512 family
Maintenance of the hydraulic drive consists in maintaining the level of the working fluid in the tank 15–20 mm below the upper edge of the filler hole, adjusting the free play of the clutch pedal and, if necessary, pumping it.
In the clutch hydraulic drive, only the free play of the outer end of the clutch release fork is regulated, which should be 2.5–3.6 mm.
This corresponds to a gap of 1.7-2.5 mm between the release levers and the clutch release bearing and a free play of clutch pedal A of 35-55 mm for all vehicles.
Adjust by changing the length of the pusher of the clutch release cylinder.
Before adjusting the free play of the clutch pedal, check the full travel of the clutch pedal (all the way to the floor), which should be 185 mm for cars of the UAZ-31512 family and 200 mm for cars of the UAZ-3741 family.
If necessary, adjust by changing the length of the pusher of the clutch release master cylinder.
Removal and disassembly of the hydraulic clutch
Remove the hydraulic clutch release from the vehicle in the following order:
- - disconnect the hydraulic hose from the working cylinder;
- – drain the fluid from the hydraulic drive through the disconnected end of the hydraulic hose;
- - remove the release spring of the clutch release fork;
- - disconnect and remove the working cylinder;
- - remove the release spring of the clutch pedal;
- - unpin and remove the pin of the pusher fork of the master cylinder;
- - Disconnect and remove the master cylinder. On cars of the UAZ-3741 family, first disconnect the tank from the flexible hose.
Disassemble the master cylinder in the following order:
- - remove the cover and strainer of the filling tank (cars of the UAZ-31512 family);
- - unscrew the fitting of the reservoir (cars of the UAZ-31512 family);
- - unscrew the body of the fitting of the flexible hose of the tank (cars of the UAZ-3741 family);
- - remove the retaining ring and thrust washer from the master cylinder body;
- - remove the piston with sealing collars, return spring from the housing.
In order to avoid damage to the sealing collars, apply compressed air to the hydraulic tube hole to remove the piston.
The fittings of the main cylinders with gaskets should not be unscrewed during disassembly, if there was no leakage of working fluid through them.
Disassemble the working cylinder in the following order:
- - disconnect the rubber protective cap from the working cylinder and remove the pusher together with the cap;
- - remove the cap from the pusher;
- - remove the retaining ring from the working cylinder body;
- - remove the piston with the sealing collar from the working cylinder; in order to avoid damage to the piston and cuff, apply compressed air to the opening for the hydraulic hose;
- - remove the sealing collar from the piston;
- - unscrew the bleed valve;
- - remove the protective cap from the valve.
Rinse the hydraulic drive parts thoroughly in brake fluid or alcohol, blow with compressed air and inspect.
Assessment of the technical condition of hydraulic drive parts
All rubber seals must be soft and elastic. Replace cuffs that are hardened, swollen or have tears and cracks on the working surfaces.
On the mirrors of the working and main cylinders there should be no scratches, shells, scuffs and significant wear.
Small traces of corrosion and slight wear can be eliminated by grinding or honing to a diameter of not more than 25.15 mm for the working cylinder and 22.2 mm for the main cylinder, with the obligatory use of only new cuffs.
Clutch hydraulic assembly
Assemble the hydraulic clutch release in the reverse order of disassembly.
Before assembling, lubricate the cylinder mirror with castor oil or fresh brake fluid.
When reassembling the master cylinder, make sure the return spring is confidently returns the piston to its original position.
Check with a soft wire with a diameter of 0.3–0.5 mm whether the cuff is blocking the compensation hole, which is completely unacceptable.
When assembling the slave cylinder, make sure that the return spring moves the piston in the cylinder confidently. Install the hydraulic drive on the car in the reverse order of removal.